A solid rear axle employing a leaf-spring suspension system as the means of attaching the solid rear axle to the chassis of the vehicle is a standard solution employed in a wide range of original equipment supplied motor vehicles such as cars, pick-up trucks and SUV's. Such leaf-spring suspensions provide, during normal usage, for the vehicle chassis to remain relatively level to the ground whilst variations in surface height are absorbed by the leaf-spring suspension in conjunction with shock absorbers. However, when subjected to increased loading, which is generally experienced only or predominantly at the rear axle of the vehicle, then these leaf-spring suspensions allow for the chassis to move downwardly towards the axle under the loading whilst maintaining the suspension's properties of isolating the chassis from the variations in the surface height within the design range of the suspension. However, the result is a chassis that is tilted downwards from front to back such that the vehicles headlights and driver's default vision are elevated away from their normal positions.
In contrast, larger articulated tractor-trailer units and heavy duty trucks typically exploit and are originally equipped with air ride suspension systems which supports the solid rear axle to the vehicle chassis and which include an air ride control system for controlling the air flow into and out of the air bladders in the air ride suspension assembly such that the air ride suspension system maintains the spacing between the axle and chassis at a predetermined distance, or within a predetermined range, regardless of the weight loading experienced by the axle. Accordingly, air ride suspension assemblies of this nature characteristically avoid unwanted rear end depression of the vehicle chassis when undergoing or experiencing increased or heavy loading over the rear axle. As such, air ride suspension systems offer enhanced performance relative to leaf spring suspensions for SUVs, trucks etc. when loaded and/or towing substantial weights.
However, despite the existence of air ride suspension systems, most leading selling SUVs and trucks are only sold by their original equipment manufacturers (OEMs) with leaf spring suspension systems. Accordingly, there exists a requirement for after-sales conversion by owners and operators of motor vehicles equipped with conventional leaf spring suspension systems to air ride suspension assembly thereby providing improved load handling and operational characteristics for their vehicles.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.